This invention relates generally to the field of collapsible reusable shipping cartons or containers, and more particularly to an improved type in which a single sealing or closure means is selectively employable to maintain the carton either in planar condition for storage, or in erected closed condition without resort to other sealing means.
Collapsible reusable shipping containers are well known in the art, in both relatively large and small sizes. For the most part they have been fabricated to include a main body element including a bottom wall and foldably attached side walls, with a separate cover element. When in collapsed condition, the side walls are folded upon the bottom wall, and the cover is then positioned to overlie the folded side walls and bottom wall to form a compact unit. In erected condition, the cover or lid is maintained upon the side walls by frictional retention, or by resort to clip and cleat means. Examples of this type of structure are disclosed in my prior U.S. Pat. Nos. 3,466,710; 3,580,618; and 4,231,149.
In relatively smaller containers, it is desirable to provide a captive lid for the purpose of simplified manufacture, and to provide increased convenience in erected and folded state. Most desirable is the provision in a container of this type of a construction in which the entire container or carton, including the cover, is formed from a single blank of planar fibrous material. Such containers are also known in the art. The principal problem with prior art constructions lies in the relative difficulty in maintaining the container in collapsed condition for storage in truly planar configuration, coupled with the relative difficulty encountered in attempting to rapidly erect the container for use. Another difficulty has been found in maintaining the container in erected condition during loading, where it has a predisposition to collapse along previously scored fold lines.